package com.concurrence.concurrence01.bhz.netty.udp;

import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.socket.DatagramPacket;
import io.netty.util.CharsetUtil;
import io.netty.util.internal.ThreadLocalRandom;

public class ServerHandler extends
	SimpleChannelInboundHandler<DatagramPacket> {

    // 谚语列表
    private static final String[] DICTIONARY = { 
    	"只要功夫深，铁棒磨成针。",
	    "旧时王谢堂前燕，飞入寻常百姓家。", 
	    "洛阳亲友如相问，一片冰心在玉壶。",
	    "一寸光阴一寸金，寸金难买寸光阴。",
	    "老骥伏枥，志在千里。烈士暮年，壮心不已!"
    };

    private String nextQuote() {
		int quoteId = ThreadLocalRandom.current().nextInt(DICTIONARY.length);
		return DICTIONARY[quoteId];
    }

    @Override
    public void messageReceived(ChannelHandlerContext ctx, DatagramPacket packet)
	    throws Exception {
		String req = packet.content().toString(CharsetUtil.UTF_8);
		System.out.println(req);
		if ("谚语字典查询?".equals(req)) {
		    ctx.writeAndFlush(
		    		new DatagramPacket(Unpooled.copiedBuffer("谚语查询结果: " + nextQuote(),
		    		CharsetUtil.UTF_8), packet.sender()));
		}
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
	    throws Exception {
		ctx.close();
		cause.printStackTrace();
    }
}
